Automatic block-signal system.



w. B, POSTER. AUTOMATIC BLOCK SIGNAL SYSTEM.

' APPLICATION TILED JULY22,1910. 1,01 1,602, Patented Dec. 12, 1911.

4 SHEETS-SHEET 1.

w, E. FOSTER. AUTOMATIC BLOCK SIGNAL SYSTEM.

1,602. APPLIOATION PILIID JULY22, 1910. Dec. 12 r 4 SHEETS-SHEET 2.

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w. E. roswnn. AUTOMATIQ BLOCK SIGNAL SYSTEM. APPLIOATIOI FILED JULY 22; 1910.

1,01 1,602. Patented Dec. 12, 1911.

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w, B. POSTER, AUTOMATIC BLOCK SIGNAL BYSTEH. APPLIOLTIOH I'ILBD JULY 22, 1910.

Patelited 1m 12, 1911.)

4 BHEBTB-EIIEET 4.

WALTER E. FOSTER, OF CHICAGO, ILLINOIS.

. AUTOMATIC BLOCK-SIGNAL SYSTEM.

Specification of Letters Patent.

Patented Dec. 12,1911.

Application filed July 22, 1910. Serial Ibl'o. 573.317.

all iv-72.0175, it may concern: Be itlinown that I, \Vaurnn E. Fos'rau, a citizen of the United States, and resident of l- Ch cago, county of Cook, and State of Ill1 now,

have invented certain new and useful Improvements in Automatic Block- Slgnal $ystems, ot which the following is a spec1- 'fication, and which are illustrated in the accompanying drawings; forming a part thereof.

The invention relates to automatic signaling systems for railways, wherein the rails of the track are divided into a plurality of insulated lengths or sections, termed blocks, which extend between the signals and. serve as conductors for a signal-controlling electric current.

The invent on contemplates a novel combination of electric block signal apparatus more particularly applicable to the operation of signals which normally give a danger or stop vindication, the term normally being used in this connection, and in the appended claims with reference to the condition of the parts when no train is pres ent in the block to which said parts immediately pertain, or in the neighboring blocks.

The object of block signal system which shall be reliable use of relays in operation and in which a reduced number ,of line wire conductors will suffice for the sion of a block in the rails of the remaining subdivision.

In the accompanying drawings-Figures 1, v2 and 3 are diagrammatic charts illustrating four consecutive sections or blocks of railway track equipped with signaling appadrawings at 8 and 9.

ratus arranged in accordance with the invention; Fi 4 is similar to Fig. 2 and-shows the use of t e relay heretofore mentioned.

The rails of a track are shown in the These rails are dithe invention is to provide a distant yided. as at 7 (Figs. .1 and 2), into a plural- 11y of insulated sections or blocks, four of which are completely shown. The several track sections or blocks, which are completely shown, are designated A, B, G and 1). respectively.

For the purpose of disclosing the inventlon, the apparatus is illustrated as taking a form adapted to operate signals for indicating the condition of the track for traffic in one direction only, and a single signal, as a, b, c, (i, is provided for each of the track sections or blocks A, B, C and D. An additional signal pertaining to a track section in advance of that designated D, is shown at e. Preferably each of the signals a, 7), c, (.l and c is of a form adapted to give three indications. As shown, so-called threeposition signals of well known construction are employed. Each signal comprises an arm 17, pivotally mounted upon a standard 18. The arm 17 indicates the signal by its positiomthe signals a, b and e being shown in the danger or stop position, the signal a being shown in the proceed or clear position, and the signal (Z in the caution position.

Each of the signals, as a, b, c and (l, is preferably located adjacent that end of the corresponding track section or block A, B, C, D, at which a train moving in the prescribed direction will enter the block. The direction of traflic, as shown, is therefore that indicated by the arrows designated 6.

The parts of the apparatus are illustrated in the positions which they will occupy when a train is in the block designated B, after having passed through the block A. Such a train is diagrammatically represented in the drawings by the truck designated 2. This truck forms an electrical short circuit or bridge between the rails 8, 9, of the track section or block which it occupies, as B.

A plurality of batteries, one for supplying electric current to the rails 8, 9, of each of the track sections or blocks A, B, C and D, are represented in the drawings at 10, 10 10, 10. These batteries are connected to the rails 8, 9, of the corresponding track section or block adjacent that end of the block at which the rails will be first engaged by a train 2 moving along the track. An electro-magnet', having a polarized armature 12 and a plurality of neutral armatures 13, 14, 15 and 16, is also in circuit with the rails 8, 9, of each of the track sections or blocks. Five such electro-magnets are illustrated in the drawings. These are designated 11, 11, 11", 11 and 11 respectively. The'electro-magnet '11 is in Circuit with the rails 8, 9, of a track section in rear of the section designated A, and the electro-magnets 11, 11", 11 and 11 are in circuit with the rails of the track sections A, B, C and D, respectively. A similar elect1-o1nagnet (not shown) will also be used in circuit with the rails 8, 9, of the track section E.

Each of the electro-m'agnets 11, 11", 11

and 1], is preferably connected to the rails of the corresponding track section at that end remote from the battery, as 10?, 10), 10 and 10 supplying current to the rails of the same section. As shown, each of these connections is made by wires designated 23, 2t.

The neutral armatures 13, 14, of each'of the electro-magnets 11, 11, 11, 11, are movable between terminals 43, 45, and .46, 47, respectively, of the corresponding batteries,

' as 10, 10, 10and 10 and constitute a poleknown construction, and is not shown in the changing switch .for the circuit including the rails 8, 9, of the next adjacent track section or block. By means of this arrangement, when the rails 8, 9, of one track section, as B, are electricallyconnected by the wheels of a train, as 2, whereby the current from the battery 10' is-shunted ofl t'rom the electro-magnet 11". the current from the ba tv tery, as 10, supplying current to the rails of the next in the rails coils of the as 11.

The signals a, b, c, d and e, by electric current served from 22", 22", 22. 22 and 22?,

track section, as C, is reversed 8, 9; of that section and in the corresponding electro-magnet,

are operated batteries, as

' other wire of the circuit for moving the signal to the caution position being desig' nated 26, and the correspoiiding wire of the circuit for moving the signal to the clear position being designated 27. The signalactuating motor is preferably housed within the signal standard 18. It may, be of well drawings. A second controlling circuit, including sections as A, B, C and D, of line wires X and Y, extending between the several signals, the same batteries 22, 22 22, 22 'and. 22*, employed for servingthe several signal operating circuits just described, may also be employed for serving the controlling circuits, including sections of the line wires X and Y.

A controlling electro-magnet as 19 19, 19, 19, and 19, islocated at each of the.

respectively. As shown, this battery current is supplied to a. signal-actuating motor for moving the signal arm 17 to the is also employed. If desired nets, as 11, 11 11 11 and 1 the electro-magnet 11.

signal stations. VVhen three-position signals are employed, as shown, each of these electro-magnets has a polarized armature 20 and a neutral armature 21. A polechanging switch, preferably operated by the movement of the signal arm 17, for changingthe direction of current in an adjacent section of the line wires X and Y, is also employed at each signal station when signals adapted to give three indications are used. As shown, each of these pole-chang iug switches includes a pair of movable blades, designated 28 and 29, respectively, =iul hcse blades are operatively connected to ilk" movable arm 17 of the corresponding signal by a pitman 30. The blades-28 and i '4'!) ccoperatewith contacts, designated 31, 32 and 33. These blades engage the contacts 31. 32, respectively, when the signal arm 17 is in its normal or danger position, indicated at a, Z) and e, and are moved to engage the contacts 32, 33, respectively when the signal blade 17 is shifted to the caution position indicated at 03-. Preferably the contacts 32, 33, are so disposed that the switch blades 28, 29, remain engaged with them upon a further movement. of the signal arm 17 to the clear position indicated at c.

The polarized armature 12 and the neutral armature 16 of each of the el'ectro-mag- 1 cooperate with contacts designated 34 and 35, respec-' tively. Both of these armatures serve as switches in the section of the line wire X which leads into a given signal station v from the next station in' advance.

When the electro-magnet, as 11, is receiving current from the battery 10 in the manner shown, the section B of the line wire X is open, both by reason of the polarized armature 12 being held out of engagement with the contact 34, and by reason of the neutral armature 16 being held out. of engagement with the contact 35. A reversal of current in the coils of the electro-magnet closes the next section of the line wire X by'. a movement of the polarized armature 12 of the electro-magnet into engagement with the contact 34. This position of the parts is shown at the electro-magnct 11, where the section I) of'the line wire X is closed by the engagement of the polarized armature 12 of the electro-magnet 11 withits contact 34. When the current from the battery, as 10 is shunted off from the coils .of the electro-magnet by a bridging of the rails'of the corresponding track section, as at z, the neutral' armature 16 is released and-closes the line wire by engagement with the contact 35-. This position of the parts is shown at The neutral armature 15 of each of the electro-l'nagnets, as 11, 11 11 1", 9 1

36 and serves as a switch of the line wire X which.

ates with a contact located inthat part engagement with the contact 36 and closes the section A of the line wire X. \Vhen, however, the battery current is shunted oil' from the electro-magnet, as at 11, by the bridging of the rails 8, 9, of the corresponding track section B by the truck .2, the armature of the electre-nmgnet 11 is released and becomes disengaged from the contact 36 to open the circuit in a section, as B, of the line wire X. The polarized armature 20 andneutral armature 21 of each of the electro-magnets 19, 19, 19 and 19". serve as switches for directing current from the battery, as 22, 22, 22, 22 and 22, into the circuit wires 25, 26 and 27 of the signal apparatus.

The polarized armature 20 cooperates with contacts designated 39 and 42, and the neutral armature 21 cooperates with contacts designated 38 and 40. Preferably the arrangement is such that when the signal arm 17 is to stand at the normal or dangerposition indicated at a, b and e, all of 'the three wires 25, 2(3 and 27, leading to its operating motor (not shown) are connected to the same pole, as 37, of a battery, as 22, 22", 22, 22 and 22. The possibility of the signal arm being operated by a foreign current is thereby precluded. This position of the parts is shown by the armatures 20 and 21 of the electro-magnets 19 and 19?, where all of the wires 25, 2G and 27, leading to the signal a and e, respectively, are shown to be connected with the pole 37 of the battery 22 or 22. Referring to Fig. 3 of the drawings, the wire 25 is directly connected to the pole 37 of the battery 22 The wire 26 is connected to this battery pole by being connected to the wire 25 by the engagement of the neutral armature 21 with the contact 38. The wire 27 is connected to the same battery pole by being connected to the wire 26 by the engagement of the polarized armature 20 with the contact 42, the wire 26 being in turn connected to the wire 25 in the manner just described.

\Vhen no train is in a given track section, as A and D, or in the section immediately in rear of it, current will be supplied to the electro-magnet, as 11, 11, from a battery, as 1O, 10, through the rails 8. 9. in the proper direction to hold the polarized ar mature 12 out of engagement with the contact 34. Each set of neutral armatures. 13, 14, 15 and 16, are therefore normally raised, the armature 15 being in engagement with the contact 36 to close that section of the line wire X leading backwardly from a given signal station, as the one having the signal e,

and the armature 16-.being out of engagement with the contact 35, whereby that section of the line wire X leading into a given signal station from the station next in advance is opened.

The presence of a train, as 2, in any track section, as B. causes current to be supplied to the coils of the electromagnet. as 19, 19, at each of two signals, as (and (I, in advance oi the train. Current is supplied to the coils of each of these electromagnets, as 19. '19. from the battery. as 22, 22. located at the signal station next in advance, as t'ollows:--Current from the battery 10 is shunted oil from the electro-magnet 11 by the bridging of the ails 8. 9, of the track section B by the train .2. All of the neutral armatures, as 13, 14, 15, 16. 0f the electromagnet 11", therefore tall. The neutral armature 16 of the electro-magnet 11", in talling, engages its contact 35, thereby electrically connecting the line wires X, Y. in the section 0 through the coils of the electromagnet 19". the connection from the line wire X to the line wire Y being by way of contact 35, neutral armature 16 of electromagnet 11 coils of electro-magnet 19. and junction -11. If no train is in track section C, current from battery 22 will now be supplied to the coils ofthc electro-magnet 19" by way of the terminal 37 of the battery 22.

wire 25 at signal (I, switch blade 28 at signal (I, contact 31 (the switch blades 28, 2!), of signal (Z not having yet been moved from the position illustrated at signals a. I). ('1, junction 53, armature 15 ot' electro-magnet 11, and its contact 36 to section C of line wire X, and returning by way of line wire Y in section'C. to contact 32 at signal (l. switch blade 29 at signal (I. to terminal 41 of battery 22.

Current from the battery 22 will be supplied to the coils of the electro-magnet 19, if no t 'ain be in either of the track sections C, D. as follows :-The neutral a'rmatures 13, 14. ot the electro-magnet 11, in fallin come into engagement with the terminals 45, t7. ot' the battery 10, whereby the current from this battery is reversed in the rails 8. 9, of the track section and in the coils of the electro-magnet 11. This throws the polarized armature 12 of the electro-magnet 11 into engagement with its contact 34. If now no train is in the track section D, so that the neutral armature 15 of the electro-magnet 11 is held in engagement with its contact 36 by current from the battery 10, current from the battery 22 will be supplied to the coils of the electro-magnet 10 by the following route :-Terminal 3.7 of battery magnets 19, 19, in the manner. just described, throws the polarized armature 20 of these magnets out of engagement with their contacts 42 and raises the neutral armatures 21 of these magnets into engagement with their respective contacts-40. Current from the batteries 22.and 22 is thereby supplied to the actuating motors of the sig-' nals c and (Z. respectively. The'signal operating circuit in each instance is the same, and that to signal 0 willbe described as follows :-The terminal 37 of battery 22,

"wire 25 at signal 0, junction 54, to signal.

wire 26 at signal 0, neutral armature 21 of electro-magnet 19, its contact 40, to battery terminal 4101 battery 22. The'blade of each' of signals 0 and d, is thereby moved out of the danger or stop position by the operation of the motor in any well. known manner. If, as shown, three-p0sition signals are employed, this movement of the signal will be in each case merely to the caution"-position. In making this movement, however, the switch blades 28, 29, connected with each signal arm 17 by the pitman 30, will be shifted from engagement with the corresponding contacts 31, 32, respectively, into engagement with contacts 32, 33. respectively, whereby the current.

from the battery 22 will be reversed in the coils of the'electro-magnet 19, causing a. further movement of the signal That is to say, when the switch blade 28, associated with the signal (Z. is in engagement with its terminal 32.. the section C of the line wire Y is connected to the terminal 37 of the battery 22, whereas the section C of the line wire X. was formerly connected with this battery terminal by the engagement of the switch blade 28 at signal (Z with its contact 31. connected with the terminal 41 of battery 22 through the armature 15 of'the electromagnet 11. the contact 33, and switch blade 29 at signal (Z.

The reversal of current in the coils of the electroanagnet 19, just described, causes the polarized armature 20 of that electromagnet 19 to be thrown into engagement with its terminal 42, and current from the battery 22 is now supplied to the actuating. motor through the wires 25 and 27. where as it was previously supplied by the wires 2) and 26. \Vith' the polarized armature 20 of the electro-magnet 19 in engagement with the contact 42. current from the battery 22 is supplied to the actuating motor of the signal a as follows :-Terminal 37 of battery 22, wire 25, junction 54 to signal a, wire 27,

The tection C of the line wire X is now polarized armature 20 ofelectro-magnet 19 contact 42, junction 55, neutral armature 21 of el-ectro-magnet. 19, contact 40, to terminal 41 of battery 22. This causes a movement of the arm 17 of the signal 0 to the clear or proceed position illustratedin the drawings. As soon as the train .2 enters the track section C, and thereby cuts off current from the battery 10- and the electro-magnet 11, current from the 4 battery 22 will be cut. off from theelectromagnet 19 by the fallingof the neutral armature 15 of the electro-magnet 11 out of engagement witlrits contact 36, and the consequent opening of the section C 'of line wire circuit X and Y. The neutral armature 21 of the eleetro-magnet 19 will then fall into engagement with its contact 38, whereby each of the wires 25, 26, 27, leading to signal 0 becomes connected to the same terminal 37 of the battery 22 as previously described, and current being thereby cutofi' from the actuating motor of the signal 0, its signal arm 17 will fall to the danger or stop .position.

Obviously, if a train had been in the track section C when the train a entered the track section B, the arm 17 of the signal 0 could not have been raised in the manner previously described, for the presence of a train in the track sect-ion C would have shunted off the battery 10 from the electro-magnet 11 and opened the section 0 of the line wire circuit X, by thefalling of the neutral armature 15 of the electro magnet 11, out of engagement with its contact 36-, thereby preventing current from the battery 22 being supplied to the electro-magnet 19.

Similarly. if a train had been in the track section D when the train a entered the track section B, the'remote signal (i would nothave been raised to the caution position in the manner previously described, for current could not have been supplied to the electro-magnet 19 from the battery 22, as the section D of the line wire circuit X, Y, would have been opened by the disengagement of the neutral armature 15 of the elect-ro-magnet 11 from its contact 36. If the remote sign'al (Z had not been raised to'the caution position there would, of course,

have-been no reversal of current in the coils of the electro-magnet 19 by the shifting of the switch blades 28, 29, associated with the signal (Z and thenear signal 0 would therefore have been moved only to the caution position, thus giving a distant indication of the presence of a train in the track section D.

In some instances it may be desirable to use a relay, as between the ends of track sections that are of unusual length. In Fig. 4 of the drawings the track section C is shown as being subdivided into sub-sections. S and T, by cutting the rails8. 9. at 56, 57,

and a relay, generally designated by the numeral 58, is employed for duplicating the "plied with current from the battery the polarized armature 61; v If, therefore, the

The electro-niagnet 59, as shown, has two polarized armatures, designated 60, 61, and two neutral armatures designated 62, 63.

The neutral armature 63 is movable into and out of engagement with a contact designated 6 1, and forms a switch in the section C of line wire X. When current from the battery 1O is shunted off from the electromagnet 59 of the relay 58, as by the presence of a train in subdivision S of the block C, the neutral armature 63 falls out of engagement with the contact 64 to open the section C of line wire circuit X, Y.

A battery, designated 65, is associated with ,the relay 58 for supplying current to the electro-magnet 11 in either direction. This battery has terminals, designated 66, 67, and 68, 69. The terminals 68 and 69 are connected to the same sides of the battery 65 as the terminals 67 and 66, respectively. The polarized armatures 60, 61, of the electro-magnet 59, are insulated from each other, and each is connected to one of the rails 8, 9, of subdivision T of the track section C. The polarized armature 61 is connected tot-he rail 9 through Wire 70, junction 71, and wire 72. The polarized armature 60 is normally connected 'to'the rail 8 through wires 73. The polarized armatures 60 and 61 are movable between the battery termi1'1als66, 68, and 67, 69, respectively. They therefore constitute a pole-changing switch located between the battery 65 and the electro'magnet 11. This pole-changing switch is operated by the reversal of current in electro-magnet 59, to produce'a similar reversal of current in electro-magnet 11.

The neutral armature 62 constitutes a switch in the wires 73, which normally connect the polarized armature 60 to the rail 8. A 'wire 76 leads from the contact 75 to the junction 71 between the wires 71 and 72. When current from thebattery 10 is shunted off from the electro-magnet 59 by the presence ofla train in the sub-division S of the track' section C, then eutral armature 62 falls out of engagement with the contact 74 and into engagement with the contact 75 thereby opening the, wire 73 leading from current from the battery 10 is reversed in the subdivision S of the track section C, that from the battery 65 will be reversed. in the subdivision T of the track section O by themovementof the polarized armaturestil),

61', of the electro-magnet 53. I If, on the tral armature 62. t1on C of 'the line wire circuit X, Y will be other hand, current from the batteries 10 is shunted off from the electro-magnet 59, that from the battery 65 will be cut of]? from the electro-magnet 11 by the falling of the neu- At the same time the secopened by the falling of the neutral armature 63.

The arrangement of relay just described will not permit a false clear or procced signal to be given, even if it should fail to operate by the adhesion of its polarized armatures 60 and 61 to the contacts which they engage. That is to sa v,if the polarized armatures 60, and 61 should adhere, as by fusion, to the terminals 68 and 69 respectively, thereby, causing current from the battery 65 to be reversed in the rails S, 9 of sub-division T, such reversal of current would only clear the signal (Z if track section D were unoccupied and if the signal (I should be thereby cleared it would return to the danger or stop position immediately upon a train entering the track section D. On the other hand, if the polarized armatures' 60, 61 should become adposition and signal 0 would be moved only to caution position when a train occupied track section B and track section C was un- I occupied. For this reason the use of relays or so-called cut sections in the normal danger system of signals is rendered quite safe by means of the invention. for the greatest disarrangement of the system which can result from a failure of the polarized armaturcs of the relay to operate is that the system shall be temporarily transformed into a normal clear system. It is'therefore unnecessary to use non-fusing contacts for the polarized armatures 60. 61 of the relay 58. Such contacts are characterized by high resistance. The arrangement described therefore has the further advantage of permitting the use of low resistance metallic contacts.

I claim as my invention- 1. In a railway signal system, in combination, a track divided into a plurality of blocks. a pair of signals, said signals being located adjacent opposite ends of an intermediate block, a movable indicating arm for one of the signals, a controlling circuit for each of the signals, a closed track circuit including the rails of said intermediate block, a second track circuit including the rails of a different block. means operated by the bridging of the rails ,ofthe last menti'oned block for .reversing th,e current v of the said signal having the movable indieating arm operated by the said reversal of current in the track circuit ofthe 1ntermediate block, and a switch in the controlling circuit of the other signal operated by the said movable indicating arm;

2. In a railway signal system,, in combination, a pair of closed track circuits, a current reverser-in each of the track circuits, a signal controlling circuit and a pair of signal operating circuits, a switch in the signal-controlling circuit closed by the reversal of current in one of the track circuits, means for reversing the current in the signal controlling circuit controlled by the reversal of current in the other track circuit, neutral means operated by the signal-controlling circuit for closing one of the signal operating circuits, and polarized means operated by the signal-controlling circuit for closing the other signal operating circuit.

In a railway signal system, in combination, a track divided into va plurality of consecutive blocks, a separate closed track circuit including the rails of each block, a signal standing normally at danger and governing traflic through the blocks in a given direction, said signal being located adjacent that end of an intermediate block at. which a train moving in the said given direction of trafiic leaves the said intermediateblock, a current reverser in the track circuit of the said intermediate block operated by the bridging of the rails of another block leading to the 'said intermediate block in the said given direction of trafiic, means tor clearing the signal controlled by the said reversal of current in the track circuit of the intermediate block, and means for preventing the operation of the signal clearing means controlled by the bridging of the rails of a block located beyond the signal in the said given direction of traffic.

4 In a railway signal system, in combination, a track divided into a. plurality of blocks, a signal governing trafiic through the blocks 1n a given direction, a normally open signal-controlling circuit, a closed track circuit 'incl'uding the rails of a block leading to the signal, a second track circuit including the rails of a block located beyond the signal, a normally closed switch in the signal-controlling circuit, a normally open switch in the signal-controlling circuit the closing of whichcloses the signalcontrolling circuit when the first-named swltch is closed, means for closing the secend-named switch operated by a reversal of current in the first-mentioned track oircuit, and means for opening'the first-mentioned switch operated by the bridging of the rails of the second-mentioned block.

5. In a railway signal system', i n combination, a track divided into a plurality of consecutive blocks, a separate closed track circuit including the rails of each block, a signal governing tratlic through the blocks in a given direction, said signal being located adjacent that end of an intermediate block at which a train moving in the said given direction of traific leaves the said intermediate block; a normally open signalcontrolling circuit, a normally closed switch in. the sigi'ial-controlling circuit, a normally open switch in-the signal-controlling circuit the closing of which closes the signalcontrolling circuit when the first-named switch is closed, a current .reverser inthe track circult of 'the sald intermediate block operated by the bridging 'ofthe rails of another block leading to the said intermediate blcck' in the said given direction of traffic, means for closing the second-mentioned switch operated by the said reversal of current in the track circuit of the said intermediate block, and means for opening the "first-mentioned switch eperated by the bridging of therails of a block located beyond the signal in said given direction of traflic.

6. In a railway signal system, in combination, a track divided into a plurality of consecutive blocks, a pair of signals governin g traflic through the blocks in a given direc tion and each standing normally at danger, said signals being located adjacent opposite "ends of an intermediate block, a separate closed track circuit including the rails of each block, a current reverser in the track circuit of the said intermediate block operated-by the bridging of the rails of another block leadingto the Said intermediate block in the said given direction of traffic, means for clearing the signal located adjacent that end of said intermediate block at which a train moving in the said given direction of traffic enters said intermediate block controlled by the. said bridging o'fthe rails of the said block which leads to the said intermediate block, means for clearing the other said signal controlled by the said reversal of current in the track circuit of the intermediate block, and means for preventing the operation of each of the said signal clearing means controlled by the bridging of the rails of a block located beyond the corresponding signal in the said given direction oftraflic. I

7. In a railway signal system, in combination, a track divided into aplurality of consecutive blocks,"a separate closed track circuit including the rails 'of each block, a pair of signals governing traflic through the blocks in a given direction, the'said signalsbeing located'adjacent opposite ends of an intermediate block, a normally open con trolling circuit for-each of the signals, a

current reverser in the track circuit of the said intermediate block operated by the bridgingof the rails of another block leadingto the said intermediate block in the said given ,direction of traffic, a switchin the controlling circuit of the signal located adjacentthat end ,of said intermediate block at which atrain moving in the said given direction of trafiic enters the said intermediate block closedby the said bridging of the rails of the saidblock which leads to the said,intermediateblock, a switch in the controlling circuit of the other signal closed by the. said'reversal of current in the track circuit-70f the said intermediate block, and a second switch in the controlling circuit of each of the signals opened by the bridging of the rails of a block located beyond the corresponding signal in t-he'said given direction of traflic. v U

In a railway signal system, in combination, a track divided into a plurality of blocks. a pair of signals, said signals being located adjacent opposite ends of an intermediate block, a movable indicating arm for one of the signals, a controlling circuit for eachof the signals, a track circuit includingthe rails of said intermediate block,

a second track circuit including the rails of a different block, means operated by 'tllO bridging of the rails of the last-mentioned track circuit for changing the electrical condition in the track circuit of the said intermediate block, a switch in the controlling circuit of the saidsignal having the mo able indicating arm operated by the said change of electrical condition in the track circuit of the saidintermediate block, and a switch in the controlling circuit of the other signal operated by the said movable indicating arm. a

9. In arailwaysignal system. in combination, a track divided into a plurality of blocks, a signal standing normally at danger and governing traffic through the blocks in a given direction, a closed track circuit including the rails of a block leading to the signal in the said given direction of traffic, a second track circuit including the rails of a block located beyond the signal in the said given direction of tr: the, means for clearing the signal normally operable either upon a reversal of current in the track circuit of the said block leat'ling to the signal or upon a bridging of the rails of the said block leading to the signal, and means for preventing the operation of the signal clean ing means controlled by a bridging of the rails he said block located beyond the signal;

10. In a railway signal system, in combination, a track divided into a plurality of blocks, a signal governing t'raflic through the blocks in a given direction, a normally open signal-controlling circuit, a closed track circuit including the rails of a block leading to the. signal, a second traclLcircuit including the rails of a block located beyond the signal, a normally closed switch in the signal-controlling circuit, a pair of I101 mally open switches, the closing of either one of which closes the signal-c1)ntrolling circuit when the first-named switch is closed, one of said socomlmentioncd switches being closed by a reversal of current in the first-mentioned track circuit and the other of said second-mentioned switches being closed by the bridging of the rails of the said block leading to the signal, and means for opening the first-named switch operated by the bridging of the rails of the said block located beyond the signal.

11. In a railway signal system, in combi nation, a track divided into a plurality of blocks, a pair of signals, said signals being located adjacent opposite ends of an intermediate block. a movable indicating arm for one of the signals, a controlling circuitv for each of the signals, a closed track circuit including the rails of said intermediate block, a second track circuit including the rails of a different block, means operated by the bridging of the rails of the last-mentioned track circuit for reversing the current in the track circuit of the said intermediate block, a switch in the controlling circuit of the said signal having the movable indicating arm operated by the said reversal of current in the track circuit of the intermediate block, a currentreyerscr in the crmtrolling circuit ot'the other signal operated by the said movable indicating arm. and incans controlled by the said reversal of current in the controlling circuit of said other; gnal for changing said signal.

12. In a 'ailway signal system, in combination. a signal adapted to give home and distant indications, a pair of normally open. signal-operating circuits operating upon the said signal, for the said home and distant indications, respectively, a normally open signal-controlling circuit, means for closing the signal-controlliug circuit, means for reversing the' current in the signal-controlling circuit, neutral incans operated by the signal-controlling circuit for closing one of said signal-operating circuits, and polarized means operated by the signal-controlling circuit for closing the other of said signaloperating circuits.

13. In a rail my signal systemqin combi- ,nation, a track divided into a plurality of consecutive blocks, a signal adapted to give three indications, a closed trii-ck circuit including the rails of one of the blocks, a second track circuit including the rails of a different block, means operated by the bridging of the rails of the said second-mentioned block for, reversing the current in the firstmentioned'track circuit, a normally open signal-controlling circuit, means for closmg 139 ,mentioned signal, a pair of closedtrack cir-- cu 1ts, one includlng' the rails of vthe said 1nthe signal-controlling circuit operated by the said bridging of the rails of the said second-mentioned block, Signal actuating means operable upon the said closing of the signalcontrolling circuit, a current reverser in the signal-controlling circuit operated by. the

said reversal of current in the first-memtioned track circuit, and other signal-actuating means operable upon the reversal of current in the signal-controlling circuit.

14(In a railway signal system,in combination, a track divided into a plurality. of

consecutive bl0cks,-a pair of signals governmg trailic through the blocks in a given direction, one of said signals being located adjacent that end of an intermediate block at which a train moving in the said given direction of t-raflic enters-said intermediate block, said signal being adapted to give three indications, and the other signal being locatedadjacent the other end of the same block, a movable indicating arm for the lasttermediate block and the other including the rails of another block leading to the said intermediate block in' the said given direction of traitic,rmeans operated by the bridging ofythe rails of the said' other block which leads to the said intermediate block for re versing the current in the'track circuit of the said intermediate block, a normally open controlling circuit for each of the said signals, means for closing the'controlling circuit of the said first described signal operated'by the said bridging of the rails of the said otherblock which leads to thesaid intel-mediate block, actuating means for the said first described signal operable upon the said closing of the controlling circuit of said signal, means for closing the controlling circuit of the said second described signal operated by the said reversal of current in the track circuit of the said intermediate block,

means for shifting the said movable indicating arm operable upon the said closing of the controlling circuit of the said second described signal, means for reversing the currentjin the controlling circuit of the said first described signal operated by the said shifting of the movable indicating arm, and

other actuating means for the first described signal operated by the said reversal of current in the controlling circuit of said signal;

15. In a railway signal system, in combi nation, a track divided into a'plurality of blocks, a separate closed track circuit including the rails of each block, asignal governing traflio through the blocks in agiven direction, said signal being located adjacentthat end of an intermediate block at Which a train moving 1n the said given d1rect1on of trafiic leaves said intermediate block, a,

current reverser in the track circuit of the .said intermediate block operated by the bridging of the rails of another block leading to the said intermediate block in the said given direction of tratfic, a'signal controlling circuit, a normally closed svvit-ch in the signal-controlling circuit, a pal r of normally open switches, the closing of e1the1' one of which closes the signal-controlling switch operated by the bridging of the rails of a block located beyond the signal in the said given direction of traflic.

WALTER E. FOSTER.

\Vitnessesz CHARLES E. GILLSQN, E. M. KLA'roHnR. 7 

